Starches and derived products — Determination of nitrogen content by the Kjeldahl method — Titrimetr...
The found value only includes free amino acids, compounds producing amino acids on hydrolysis and ammonium compounds. The principle consists in destruction of organic matter by sulphuric acid in the presence of a compound catalyst (see ISO 1871), alkalization of the reaction products, distillation of the liberated ammonia and collection in a boric acid solution, followed by titration with a…
Corrigendum 1 - Determination of the aromatic hydrocarbon content of new mineral insulating oils
Applies to quality control and acceptance testing of oils. Two methods of analysis are given: infra-red spectrophotometry and adsorption chromatography.
Hardmetals — Determination of contents of metallic elements by X-ray fluorescence — Solution method
The solution method determines cobalt, iron, manganese, molybdenum, nickel, niobium, tantalum, titanium, tungsten, vanadium and zirconium. Is applicable to carbides of niobium, tantalum, titanium, vanadium, tungsten and zirconium, mixtures of these carbides and binder metals, all grades of presintered or sintered hardmetals, produce from these carbides, with the minimum element contents shown in…
Caseins and caseinates — Determination of protein content (Reference method)
Does not apply to caseins and caseinates containing ammonium caseinate or other ammonium compounds, or other nitrogenous nonprotein compounds. The principle of determination consists in digesting a test portion with a mixture of potassium sulphate and sulphuric acid, in the presence of copper(II) sulphate as catalyst, to convert organic nitrogen into ammoniacal nitrogen, distilling and absorbing…
Meat products — Determination of starch content (Reference method)
The method consists in heating a test portion with ethanolic potassium hydroxide solution until the meat components are totally dissolved, decanting, washing of the remaining residue with hot ethanol, filtering, dissolving in hydrochloric acid, and hydrolysis, followed by titrimetric determination of the glucose formed.
Hardmetals — Determination of contents of metallic elements by X-ray fluorescence — Fusion method
Specifies methods for the determination of the presence, type, and distribution of porosity and uncombined carbon in hardmetals, furthermore apparatus, preparation of test pieces, procedure and test report. Figures show the types of apparent porosity and uncombined carbon.
Starches and derived products — Determination of nitrogen content by the Kjeldahl method — Spectroph...
Destruction of organic matter by sulphuric acid in the presence of a compound catalyst (see ISO 1871), alkalization of the reaction products, destillation of the liberated ammonia and collection in a sulphuric acid solution, followed by measuring of the ammonium salt formed after the addition of Nessler reagent. The method is provided for contents less than 0,025 % (m/m). For greater contents,…
